NASA: National Aeronautics and Sea Administration? The U.S. space agency will send a crew to the bottom of the Atlantic Ocean this summer in preparation for future spacewalks.

The 14-day NASA Extreme Environment Mission Operations (NEEMO) 20 expedition is slated to begin July 20.

During the two-week deep-sea excursion, the group will evaluate tools and techniques for use in possible space missions (like the surface of asteroids or the moons of Mars).

"Living and working in the highly operational, isolated, and extreme environment of the aquatic realm has provided significant science and engineering for the benefit of human spaceflight," project lead Bill Todd said in a statement. "It has also clearly proven to be as close to spaceflight as is possible here on Earth."